In most incidences of thoracic surgery, including cardiovascular surgery, the operation necessitates the surgical division of the patient's sternum, such that the thoracic basket, or rib cage, can be prised apart. The division of the rib cage allows the surgeon access to the patient's thoracic cavity.
To effect the division of the sternum, generally, the patient's sternum is split by the use of a chest saw, and the two halves held apart using a retractor.
From the clavicle downwards, there are three main parts of the sternum—the manubrium, body and the xiphoid process. The three parts form the middle portion of the anterior wall of the thorax. The manubrium supports the clavicles, and the peripheries of the manubrium and body support the first seven pairs of ribs.
Conventional open-sternum surgery inflicts significant patient trauma and discomfort, requires extensive recuperation times, and may result in lifethreatening complications.
Incisions made over the chest are especially painful. The pain is unavoidable because movement exacerbates pain and the chest moves with respiration.
A significant amount of blood is typically lost from the raw surfaces of the two sides of the cut sternum. The need for blood transfusion is therefore relatively high.
Heat loss from wet surfaces is significant from open sternal wounds.
Chest incisions made through splitting the sternum only heal as fast as the fracture in the breastbone can heal. It typically takes several months for the bone to unite fully.
In some patients the fracture does not heal or becomes infected. This leads to long-term problems with stability of the chest cage or life threatening sepsis.
Furthermore, when the rib cage is divided using a conventional prior art sternal spreading retractor, more stress is placed on the shorter upper ribs than the longer lower ribs sometimes resulting in broken ribs.
Finally, the division of the chest can also lead to patients suffering from neurological disorders following open chest surgery, such as numbness in the hands.
To mitigate the damage that can be caused to the smaller upper ribs, which are connected to a neurologically important part of the plexus, surgeons have attempted to formulate more satisfactory ways of dividing the sternum and holding it thus.
One such idea has been to position the retractor in a lower position on the sternum to minimise damage to the weaker upper ribs. Such positioning has been found to result in less rib breakages, but the uneven pressure of the placement occasionally causes sternal fracture, leading to complications such as increased bleeding during surgery, and the need for repeated surgery to correct the sternal damage.
Accordingly, it would be desirable to provide minimally invasive chest cavity access through a neck incision, which has many potential benefits:                Less pain and trauma        Less bleeding        A smaller incision        Less heat loss during surgery        Reduced risk of infection        Decreased length of stay in hospital post procedure        Decreased recovery time        
Incisions made in the neck fall outside of the area of the body that moves with respiration so a wound here is inherently less painful. In addition it is easy to infiltrate the neck area with local anaesthetic. This can abolish pain altogether.
Less pain means less need for analgesia. The latter have side effects including sedation at higher doses. The reduced requirement for analgesia will enable patients to waken from anaesthesia more quickly and to breathe spontaneously.
Heat loss from wet surfaces is much less from a small neck incision than an extensive open sternal wound.
Blood loss will be minimal through a small neck incision in comparison to open sternal incisions. Because no bone is divided and bone marrow is not exposed.
Neck incisions heal more quickly than conventional open-chest incisions. This is because they are smaller and the skin and soft tissues of the neck have a much better blood supply than those over the chest. The latter also reduces potential infections.
The present invention obviates or mitigates the foregoing deficiencies of the prior art devices and methods.